As the volume of renewable energy increases, the need for new storage technologies increases. The Scottish company Gravitricity is working on a new pilot plant that will store gravitational energy by lifting and lowering heavy loads weighing between 500 and 5, 000 tons.
The principle of operation of such an installation is quite simple: loads held in the air with the help of ropes and powerful winches have a large amount of potential energy. If necessary, they can be lowered down the vertical shaft of the mine with a depth of 150 to 1500 meters. As conceived by the developers, for this you can use abandoned mines.
According to Gravitrisity, by manipulating the blocks, it is possible to obtain from 1 to 20 MW of electricity, and the installation itself will be able to operate for up to 50 years without loss of performance. It is capable of reaching maximum power in less than a second and then releasing the stored energy within 15 minutes or, in slow motion, for up to eight hours.
The lifting of the load is carried out by powerful electric winches connected to renewable energy sources. According to experts, the efficiency of such a system is 80-90%. As a result, it is able to store energy at a lower cost compared to, for example, Tesla's huge lithium-ion battery in Australia.
Gravitricity is currently in the early stages of building an experimental demonstration facility, which is expected to begin testing next year. It is a tower with a height of 16 m, the size of the lifted load is two blocks of 25 tons each, with the help of which up to 250 kW of electricity will be accumulated and released.